I'll echo what Doug has said. I'm an avid (some would say rabid) fan of the Rittergrips. I'll get a fixed blade too when they come out as well for use in the outdoors and around the house where I prefer a fixed blade. However, a folder is definitely easier to pack around in populated areas. I use both my large and my small Rittergrips equally, depending on where I'm going to be working or socially visiting. My dad on the other hand, sticks to his small Rittergrip and doesn't see any need for a large, but he's never been fond of any large folding or fixed blade knife, whereas I do like the larger folders. I basically only use a small folder when I'm in urban/domestic PHRASECENSOREDPOSTERSHOULDKNOWBETTER. territory and don't want folks to be too startled when I use my knife for some chore of my own or theirs (as they almost never have a knife of their own).

You can basically carry a folder just about anywhere and there are definitely social reasons to have both large and small models. I won't address any legal issues of carry a folder since those laws vary so widely. I don't personally worry so much over laws unless there are armed security people and metal detectors because that indicates to me a general level of hysteric paranoia so I generally avoid those kinds of places or comply strictly with the law when work requires me to be there. I'm more of a spirit of the law kind of person and pretty much do as I will with regard to pocket knife laws and try to respect whatever local social customs exist. Essentially, I act as any reasonable and responsible person would and should, and don't fret over the libraries full of laws that entangle our nation. Beg pardon for my digression.

Anyway, I'd strongly encourage you to at least get a small folding Rittergrip and then get the fixed blade when it comes out. I'd heartily recommend you get small, large and fixed since I think they all have their valid place and use.